My brother is 18 and he has anger issues. It won't be long until it will ruin our family relationship forever. There has not been one conversation that I have ever had with him where in the end it will turn into a huge argument, he will be swearing at me in a violent way, and may even physically ,on rare occasions, hit me.

For instance I try and be nice and ask him a simple question, he can't help but end up calling me ''stupid'' or a ''f*ggot'' and without a swear word in a sentence. He is absolutely disrespectful to our parents. He ignores them, tells them to 'shut up'' and is arrogant, argumentative, aggressive and insolent towards them. Even when they are trying to talk to him and be nice to him, he can't even say 'Thank you'' without mumbling it.
I think it may have started when he was 13/14. I realised he started mixing with the wrong group of friends and having them influence on him. And now he is in college it's even worse. He started drinking, going out and coming home late and not telling anyone where he is. My parents don't know about him drinking and anything else because he doesn't tell them anything. His grades in college are also dropping severely and he's always going on about giving up this and that.

Talking to him about this is Out of the question. He won't listen, he always thinks he is right, he always thinks we are in the wrong when in fact, he can't just admit he is wrong, back down and get off his high horse.
The way he speaks to my mother is unbelievable too. I know she is hurt by all this. He doesn't care. he doesn't care about anything, or anyone apart from himself! He doesn't realise how much they care about him and he can't appreciate anything. I could say his personality and everything has gotten even worse.

May be this is just what teens will go through and will grow out of, but I'm scared he might turn out to be an alcoholic and doing things he shouldn't be doing! If we did try counselling, I know that he would refuse to go.
I can't ignore this and hope that it will go away because I just can't stand it any more. I can't eve bare to look at him any more. He's become like some sort of stranger to me and also around the house.

I'm so sorry your brother is out of control. You need to get a family or friend intervention and get a place he can go for his alcohol or drug addiction and anger management. You need to get your mom and dad to stop enabling him to treat them disrespectfully and one day he may hurt them. He should never hit anyone. He is an adult so he needs to take responsibility for his actions and if you have to call the police then do so. I know it is scary but someone has to get to the root of his problems. Being a teenager doesn't give him the right to be disrespectful and hurtful to his family. Please try to find someone to intervene and help you all.